Research examining the relationship between smoking and menstrual cycle has produced conflicting findings. It has been suggested that women may smoke more during the late-luteal phase of their cycle, presumably to manage dysphoria. This study examines the relationship between smoking (ad-lib vs. abstinence) and menstrual cycle phase. The aims of this study are to charactize the effect of smoking condition and menstrual cycle phase on: 1) smoking behavior; 2) mood states; 3) tobacco withdrawal symptoms; and 4) menstrual symptoms in young adult women smokers during two consecutive menstrual cycles.